Reverse Engineering of Existing Software

When the original developers are no longer available or documentation is missing, existing software can be difficult to extend or migrate. Through structured reverse engineering, I analyze the architecture, data flows, and business logic of existing applications.

The goal is to make grown or overly complex systems understandable and maintainable again—whether they are in-house developments, older commissioned projects, or mixed environments.

This includes analyzing source code, reconstructing modules, interfaces, and data models, and preparing the application for extensions, bug fixes, or complete modernization.

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FAQ: Reverse Engineering

Explained briefly—without too much technical detail: Here are the most common questions about reverse engineering and how I approach it.

What is reverse engineering?

Reverse engineering means that I analyze existing software so its behavior becomes understandable again — even if documentation is missing or the original developers are no longer available. The goal is to understand the structure, data flows, and underlying logic.

What is it good for—do I need it?

This is helpful when an application is business-critical but no longer maintained — and therefore can no longer be extended or adapted — or when the operating system it runs on is no longer supported and has become vulnerable (Windows 10, Windows XP, DOS, …). In the end, the core logic can be reliably reproduced, selectively extended, or used as a solid basis to plan a modernization or migration safely.

What do you need for a reverse-engineering project?

Ideally, a working reference setup: the program in a functioning state — incl. sample data, typical workflows, and (if available) installation files or configuration. The better the starting point, the faster we can reach reliable results.

How does reverse engineering work?

I proceed in a structured way: first I gain an overview, then I review workflows and trace the logic step by step. Depending on the starting point, this can be quick — or more time-consuming. Along the way, you receive intermediate results and a transparent assessment of effort and next steps.

What outcomes can I expect in the end?

Typical results include clear documentation of the most important functions and dependencies, an overview of data and interfaces, and a well-founded recommendation on whether an extension makes sense or whether a modernization/new implementation is the better fit.

How long does such a project take?

That depends heavily on whether documentation is available and how complex the software is. That’s why I usually start with a short analysis phase. After that, effort and approach can be estimated much more reliably.

Is reverse engineering legally permissible?

I only work on the basis of your authorized use (e.g., if you have rights to the system or it is used within your organization). If licensing or IP questions are relevant, we clarify them upfront — transparently and properly.

Custom software development is always calculated based on actual effort

Software development is inherently individual and depends on the specific requirements of each project. Existing systems, integrations, and technical conditions vary from case to case.

Therefore, timelines, scope, and costs are always determined transparently, based on the actual effort involved and the unique circumstances of your project.